Meningitis
什么是Meningitis？
Meningitis (inflammation of the linings of the brain) can be caused by many types of organisms, such as bacteria and viruses.
Meningococcal meningitis is caused by a specific bacterium known as N. meningitides. In addition to several types of N. meningitidis, another common bacterium that can cause meningitis is called Streptococcus pneumoniae. There are 83 known types of Streptococcus pneumoniae. Usually this streptococcus bacteria causes pneumonia in the lungs. However, this organism may spread through the blood to infect the linings of the brain.
In countries where the disease is common, up to 5 to 10 percent of the general population will carry the N. meningitidis bacterium in their nose or throats.
Another form of meningitis is called aseptic meningitis. The most common cause of aseptic meningitis is a viral infection, and enteroviruses are common causes of viral meningitis, especially in children during the summer months. However, aseptic meningitis may be caused by other viruses, such as arboviruses, HIV, herpes simplex virus (HSV) types 1 and 2, some bacteria, fungi, and parasites. Most people who get infected with enteroviruses are asymptomatic or have only a general febrile illness.
如何获得Meningitis？
Person-to-person transmission occurs by inhaling respiratory droplets containing the bacteria or virus or by close contact with an infected person’s respiratory secretions or saliva.
Enteroviruses are most often spread via the fecal-oral route from person to person through fecal contamination of water or food or contact with contaminated inanimate objects. Enteroviruses can also be spread through respiratory secretions (saliva, sputum, or nasal mucus) of an infected person
易感性和抗性
General susceptibility is low. The disease is most common in very young children or young adults. Excessive crowding contributes to the spread of bacterial meningitis. Susceptibility generally decreases with age.
症状是什么？
The illness usually involves the sudden onset of fever, severe headache, a stiff neck, nausea with some vomiting, and may be accompanied by a small rash. The patient may become confused and delirious and enter into a coma, sometimes very quickly after the onset of the illness. Unless the illness is diagnosed early and treated rapidly and aggressively with antibiotics and other supportive measures, the fatality rate can be quite high. With early and aggressive treatment with antibiotics for bacterial meningitis, the death rate has been reduced to between 5 and 15 percent.
Antibiotics are not effective for aseptic meningitis caused by viruses. However, most people who get infected with enteroviruses are asymptomatic or have only a general febrile illness.
预防措施
对于那些在流行病国家（即撒哈拉以南非洲）旅行或居住的人们，建议接种由细菌引起的脑膜炎奈瑟菌疫苗。当在其他地区有很多病例或这种细菌爆发时，也可能建议接种疫苗。美国疾病控制与预防中心建议对所有11至12岁的青少年和青少年接种脑膜炎球菌结合疫苗，并在16岁时加强剂量。青少年和年轻人（16至23岁）也可以接种B血清群脑膜炎球菌疫苗。如果他们存在以下疾病：诸如脾脏受损或缺失，免疫系统受损或属于因B群脑膜炎球菌疾病暴发而增加风险的人群。对于直接接触细菌性脑膜炎的人，建议使用抗生素预防接触者的疾病。在美洲，欧洲，澳大利亚，中国和印度，已经出现了耐环丙沙星的脑膜炎球菌病的零星分离株。因此，美国疾病控制与预防中心建议，在已确定具有环丙沙星抗药性菌株的社区中，不应再将环丙沙星用于脑膜炎球菌的化学预防。现在推荐使用头孢曲松，利福平和阿奇霉素。遵循一般的食物和水预防措施并保持谨慎的个人卫生习惯将有助于预防由肠病毒引起的无菌性脑膜炎。
处理
Early and aggressive treatment with a variety of commonly available antibiotics is generally effective. For aseptic meningitis, only general supportive measures are available.
药物
疫苗接种
它常见于哪里？
脑膜炎球菌感染在世界任何地方都被发现，病例通常是零星的。非洲撒哈拉以南国家在旱季（通常是从12月至4月）经常出现细菌性脑膜炎的流行。这些国家被称为撒哈拉以南的脑膜炎带，包括冈比亚、塞内加尔、马里、布基纳法索、加纳、尼日尔、尼日利亚、喀麦隆、乍得、中非共和国、苏丹、乌干达、肯尼亚、埃塞俄比亚和厄立特里亚。
肠病毒是无菌性脑膜炎的主要原因，全世界都有这种病毒。
